Ballast water treatment apparatus

Abstract

To provide a ballast water treatment apparatus capable of determining a proper operation mode.According to the present invention, a ballast water treatment apparatus includes a flow rate adjustment section configured to adjust the treatment flow rate of the flowing ballast water, an ultraviolet reactor capable of adjusting an ultraviolet irradiation amount, a transmittance acquisition section configured to acquire the ultraviolet transmittance of the flowing ballast water, and a control section configured to control the flow rate adjustment section and the ultraviolet reactor in one operation mode selected from multiple operation modes. In each of the multiple operation modes, the treatment flow rate and the ultraviolet irradiation amount are defined for each ultraviolet transmittance. The control section acquires the ultraviolet transmittance from the transmittance acquisition section before the purification treatment, and determines a proper operation mode based on the ultraviolet transmittance as a determination reference.

What is claimed is: 
     
         1 . A ballast water treatment apparatus for performing purification treatment for flowing ballast water, comprising:
 a flow rate adjustment section configured to adjust a treatment flow rate of the flowing ballast water;   an ultraviolet reactor capable of adjusting an ultraviolet irradiation amount;   a transmittance acquisition section configured to acquire an ultraviolet transmittance of the flowing ballast water; and   a control section configured to control the flow rate adjustment section and the ultraviolet reactor in one operation mode selected from multiple operation modes,   wherein in each of the multiple operation modes, the treatment flow rate and the ultraviolet irradiation amount are defined for each ultraviolet transmittance, and   the control section acquires the ultraviolet transmittance from the transmittance acquisition section before the purification treatment, and determines a proper operation mode based on the ultraviolet transmittance as a determination reference.   
     
     
         2 . The ballast water treatment apparatus according to  claim 1 , wherein
 the transmittance acquisition section is a transmittance measurement sensor configured to measure the ultraviolet transmittance, and   the control section acquires the ultraviolet transmittance from the transmittance measurement sensor.   
     
     
         3 . The ballast water treatment apparatus according to  claim 1 , wherein
 the transmittance acquisition section holds previous operation data, and predicts a current ultraviolet transmittance from the previous operation data in advance, and   the control section acquires the predicated ultraviolet transmittance.   
     
     
         4 . The ballast water treatment apparatus according to  claim 1 , wherein
 the transmittance acquisition section acquires the ultraviolet transmittance in a preliminary operation of discharging the ballast water without the ballast water being stored in a ballast tank, and   the control section acquires the ultraviolet transmittance from the transmittance acquisition section.   
     
     
         5 . The ballast water treatment apparatus according to  claim 1 , wherein
 the control section acquires an acceptable treatment time for ballast operation and compares the acceptable treatment time and necessary treatment time for each operation mode, the necessary treatment time being calculated from the treatment flow rate corresponding to the ultraviolet transmittance acquired from the transmittance acquisition section.   
     
     
         6 . The ballast water treatment apparatus according to  claim 1 , wherein
 for each of the multiple operation modes, a tank holding time for which treated ballast water needs to be held in the ballast tank is set, and   the control section acquires an acceptable discharge time until the ballast water treated by the ultraviolet reactor is discharged after having been stored in the ballast tank, and compares the acceptable discharge time and the tank holding time.   
     
     
         7 . The ballast water treatment apparatus according to  claim 6 , wherein
 the multiple operation modes include a first mode and a second mode,   the treatment flow rate in a case where the ultraviolet transmittance is equal to or higher than a predetermined value is set higher in the first mode than in the second mode, and   the treatment flow rate in a case where the ultraviolet transmittance is lower than the predetermined value is set higher in the second mode than the first mode.   
     
     
         8 . The ballast water treatment apparatus according to  claim 1 , wherein
 in a case where control is able to be performed in any of the multiple operation modes, an operation mode with a smaller power consumption is determined as the proper operation mode.